Name,Description,Reference
filename,name to be used when creating file,[RFC2183]
creation-date,date when content was created,[RFC2183]
modification-date,date when content was last modified,[RFC2183]
read-date,date when content was last read,[RFC2183]
size,approximate size of content in octets,[RFC2183]
name,original field name in form,[RFC7578]
voice,type or use of audio content,[RFC2421]
handling,whether or not processing is required,[RFC3204]
preview-type,Internet media type (and parameters) of the preview output desired from a processor by the author of the MIME content,[RFC7763]
reaction,"Permit a recipient to respond by signaling basic
        reactions to an author's posting, such as with a 'thumbs up' or
        'smiley' graphic",[RFC9078]